Experience-dependent plasticity in S1 caused by noncoincident inputs
Experience-dependent plasticity in S1 caused by noncoincident inputs
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DOI：
10.1152/jn.00172.2005
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发表时间：
2005-09-01
影响因子：
2.5
通讯作者：
Merzenich, MM
中科院分区：
文献类型：
--
作者：
Blake, DT;Strata, F;Merzenich, MM
先前的工作表明，一致的输入成为共同代表在躯体感觉皮层。在这项研究中，假设数字的共同表征需要同步的输入进行了测试，并与皮层植入观察两个数字的感受野的日常发展。两个成年灵长类动物检测到的时间差异，在水龙头对交付给两个相邻的数字。随着刺激起始时间>= 100 ms，在训练的前4周，表征改变为包括两位数的感受野。此外，感受野在网站响应的水龙头扩大了两倍以上，和感受野在网站没有响应的水龙头没有显着的面积变化。进一步的训练没有增加两位数感受野的表达。皮层反应的水龙头不依赖于间隔的长度。刺激之前的命中，错过，假阳性，真阴性不同的是在进行中的皮质率从50至100毫秒的刺激后，但没有不同的初始，主要，响应水龙头。对紧急反应的反应延迟平均比旧反应长4.3 ms，如果可塑性起源于皮层，则会发生这种情况。新的反应相关性与新的感受野平行发展。这些数据表明，共表征可以引起的呈现刺激在一个更长的时间窗口比预测的尖峰时间依赖的可塑性，并建议增加皮层兴奋性伴随着新的任务学习。
Prior work has shown that coincident inputs became corepresented in somatic sensory cortex. In this study, the hypothesis that the corepresentation of digits required synchronous inputs was tested, and the daily development of two-digit receptive fields was observed with cortical implants. Two adult primates detected temporal differences in tap pairs delivered to two adjacent digits. With stimulus onset asynchronies of >= 100 ms, representations changed to include two-digit receptive fields across the first 4 wk of training. In addition, receptive fields at sites responsive to the taps enlarged more than twofold, and receptive fields at sites not responsive to the taps had no significant areal change. Further training did not increase the expression of two-digit receptive fields. Cortical responses to the taps were not dependent on the interval length. Stimuli preceding a hit, miss, false positives, and true negatives differed in the ongoing cortical rate from 50 to 100 ms after the stimulus but did not differ in the initial, principal, response to the taps. Response latencies to the emergent responses averaged 4.3 ms longer than old responses, which occurs if plasticity is cortical in origin. New response correlations developed in parallel with the new receptive fields. These data show corepresentation can be caused by presentation of stimuli across a longer time window than predicted by spike-timing-dependent plasticity and suggest that increased cortical excitability accompanies new task learning.